Check the protein percentage. It may be on the high side for chickens.
I do the FF. When I first start it I put about a glug of ACV in the bucket, add feed and water to completely cover it(no air, anerobic is better), stir it up and check in 30 minutes to make sure is still covered with water, add more if needed. Cover bucket with a towel and stir twice a day for 2 days. Should start having bubbles in the mix at this point. That means it's ready to start feeding. I pour off the excess water mix into a new bucket and add more feed and water to it for the next day. The first batch you can feed as is to them or mix a little dry in to get a thicker feed(this is what I do, like thick oatmeal) and put in a dish to feed them. Keep this rotating process up every morning. Older birds may take a little while to adjust but when they are hungry enough they will eat it. And it smell real good, like bread dough kinda
I had one of M Best silkie chicks do this, she still cleans the cockerel's beard and crest of feed. She is not aggressive in any way.
Thanks. She is a little different than the rest. A real show stealer I hope.